<template>
    <div class="bg">
        <div class="a"></div>
        <div class="b"></div>
        <div class="c"></div>
    </div>
</template>

<script>
export default {

}
</script>

<style scoped>
.bg {
    background-color: #eeee;
    width: 100%;
    height: 1000px;
    position: relative;
}

.bg>div {
    position: absolute;
    left: 50%;
    top: 50%;
    border-radius: 50%;
    transform: translate(-50%, -50%);
}

.a {
    width: 450px;
    height: 450px;
    border-radius: 50%;
    border: 2px solid white;
    animation: a 5s linear infinite;
    transform: translate(-50%, -50%) scale(1.8);
}

.b {
    width: 340px;
    height: 340px;
    background-color: rgba(255, 255, 255, .4);
    animation: a 5s linear infinite;
    transform: translate(-50%, -50%) scale(1.8);
}

.c {
    width: 450px;
    height: 450px;
    background-color: white;
    animation: c 5s linear infinite;
}

@keyframes a {
    0% {
        transform: translate(-50%, -50%) scale(1.8);
        opacity: 1;
    }

    50% {
        transform: translate(-50%, -50%) scale(2);
        opacity: .5;
    }

    100% {
        transform: translate(-50%, -50%) scale(1.8);
        opacity: 1;
    }
}

@keyframes c {
    0% {
        transform: translate(-50%, -50%) scale(1);
    }

    50% {
        transform: translate(-50%, -50%) scale(1.1);
    }

    100% {
        transform: translate(-50%, -50%) scale(1);
    }
}
</style>